1. Field of the Invention
The present invention relates to the field of portable computer systems. Specifically, the present invention relates to a relocatable and universal interface module for a display device that can be installed in different portable computer system designs.
2. Related Art
As the components required to build a computer system are reduced in size, new categories of computer systems are emerging. One of the more recent categories of computer systems is the portable, or xe2x80x9cpalmtop,xe2x80x9d computer system or personal digital assistant (PDA). A palmtop computer system is a computer that is small enough to be held in the hand of a user and is thus xe2x80x9cpalm-sized.xe2x80x9d As a result, palmtops are readily carried about in a briefcase or purse, and some palmtops are compact enough to fit into a person""s pocket. By virtue of their size, palmtop computer systems are also lightweight and so are exceptionally portable and convenient.
Because of their relatively small size, designers of portable computer systems are faced with the challenge of having to fit the various internal components as efficiently as possible into a small housing. This task is complicated because there may be different models built on the same basic platform. Each model may require a different hardware configuration depending on the features it incorporates, yet the internal components must still fit into the standard-size housing.
For example, a palmtop computer system may utilize either a monochrome display device or a color display device. The display screen for the color device is typically thicker than the screen of a monochrome device, and generally there are differences between the circuitry needed to connect and drive a monochrome display device versus a color display device. The display device is typically connected to a printed circuit board, and thus different printed circuit board designs are needed to accommodate differences in the connection circuitry. Each version of a component increases the number of parts to be tracked and managed, thereby complicating the design process.
Variability in design may also be introduced by the different manufacturers and vendors of display devices, each of which may have their own connector scheme and interface circuitry. Thus, the number of printed circuit board designs is increased further to accommodate the different manufacturers, adding more parts that need to be tracked.
Consequently, considering just the display device and associated circuitry, a designer attempting to determine the layout of the components in a portable computer system design must contend with a number of variables. This issue is exacerbated in view of the number of other components that may be used in a palmtop computer system.
In addition, the different types of interface circuitry leads to increased manufacturing costs; specifically, increased tooling costs. For each combination of a monochrome display and interface circuitry, tooling costs can be as much as $100,000, and for each combination of color display and interface circuitry, tooling costs can be as much as $1,000,000.
The layout design process is further complicated by the fact that, even after a layout is decided on, it may need to be modified in order to accommodate design changes, such as the addition of new features or increased capabilities. For example, it may be desirable to add a radio, to relocate an existing component such as a battery, or to add or relocate expansion slots. Because internal components are typically packed fairly tightly together in a palmtop computer system, any significant change will likely make it necessary to rearrange multiple components.
Thus, the layout design process for a portable computer system, and for other similarly complex portable devices, can be complicated and difficult, increasing lead times, development costs, and manufacturing (e.g., tooling) costs.
Accordingly, what is needed is a system and/or method for simplifying the layout design process for portable devices such as portable computer systems. What is also needed is a system and/or method that accomplishes the above but still allows a degree of flexibility for accommodating design changes. The present invention provides these advantages and others not specifically mentioned above but described in the sections to follow.
The preferred embodiment of the present invention pertains to a portable computer system (e.g., a palmtop or hand-held computer system) with an interface module. In the preferred embodiment, the interface module is coupled between a device and a printed circuit board. The interface module includes circuitry needed to connect with the device and drive the function of the device. Thus, this circuitry does not need to be located on the printed circuit board of the portable computer system. Accordingly, the interface module provides a technology-independent architecture which can be used with different device technologies.
In one embodiment, the interface module is coupled to the device using a first flexible circuit, and coupled to the printed circuit board (e.g., a central processing unit) using a second flexible circuit. The interface module is pivotable about the first flexible circuit so that it can be positioned in different locations within the computer system, depending on space availability and the constraints of a particular computer system design. In this embodiment, the interface module can be flipped from one location to the other, with the first flexible circuit in effect acting as a hinge; in this case, the second flexible circuit can be inverted and coupled to the printed circuit board.
In one embodiment, the interface module and the first flexible circuit are integrated into a single flexible circuit. In another embodiment, the interface module and the second flexible circuit are integrated into a single flexible circuit.
In one embodiment, the device is a display device. In this embodiment, the interface module contains interface circuitry needed to connect with and operate the display device. In accordance with the present invention, a particular supplier can provide the interface module, which would be populated with circuitry according to the supplier""s interface scheme. The circuitry in the interface module also depends on whether it is intended for a monochrome display or for a color display.
Thus, in accordance with one embodiment of the present invention, the combination of a device (e.g., a display device) and an interface module, including a flexible circuit, can be implemented in different designs of portable computer systems, simplifying the design process and significantly reducing development time and manufacturing costs. During product development, leveraging the use of an interchangeable, relocatable interface circuit module across different portable computer system designs can enable faster time to market.
In another embodiment, the interface module can be coupled to a device (e.g., a display device) and/or to the printed circuit board using connectors other than flexible circuits. This embodiment is still advantageous because the interface module provides a universal interface with any of the various types of display technologies and thus is a technology-independent architecture.